Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New NASA Model Gives Glimpse into the Invisible World of Electric Asteroids

26.06.2014

Space may appear empty -- a soundless vacuum, but it's not an absolute void. It flows with electric activity that is not visible to our eyes. NASA is developing plans to send humans to an asteroid, and wants to know more about the electrical environment explorers will encounter there.

A solar wind blown from the surface of the sun at about a million miles per hour flows around all solar system objects, forming swirling eddies and vortices in its wake. Magnetic fields carried by the solar wind warp, twist, and snap as they slam into the magnetic fields around other objects in our solar system, blasting particles to millions of miles per hour and sending electric currents surging in magnetic storms that, around Earth, can damage sensitive technology like satellites and power grids.


This is a concept image of an astronaut preparing to take samples from a captured asteroid. The sun is in the background; NASA wants to know more about electrical activity generated by the interaction of solar wind and radiation with asteroids.

Image Credit: NASA


Electric field direction (arrows) and strength (colors) produced by the simulated interaction of the solar wind with a small irregularly shaped asteroid, about 150 meters (yards) long by 50 meters wide. The deepest shades of red indicate strong and possibly hazardous electric fields.

Image Credit: NASA/JHU-APL/Michael Zimmerman

On airless objects like moons and asteroids, sunlight ejects negatively charged electrons from matter, giving sunlit areas a strong positive electric charge. The solar wind is an electrically conducting gas called plasma where matter has been torn apart into electrons, which are relatively light, and positively charged ions, which are thousands of times more massive. While areas in sunlight can charge positive, areas in shadow get a strong negative charge when electrons in the solar wind rush in ahead of heavier ions to fill voids created as the solar wind flows by.

The surface of Earth is shielded from the direct effects of this activity by our planet's magnetic field, but airless objects without strong repelling magnetic fields, like small asteroids, have no protection from electrical activity in space.

NASA-sponsored researchers funded by the Solar System Exploration Research Virtual Institute (SSERVI) (formerly the NASA Lunar Science Institute (NLSI)) have developed a new computer model that can predict and visualize the interaction between the solar wind, solar radiation, and the surface of asteroids in unprecedented detail. 

"Our model is the first to provide detailed, two-dimensional views of the complex interaction between solar activity and small objects like asteroids, using an adaptive computational technique that makes these simulations highly efficient," said Michael Zimmerman, project lead at the Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

Previous "grid-type" models are less efficient at calculating the effects of solar activity on complex surfaces like asteroids because they devote computer resources equally to all areas, according to Zimmerman. His new "tree code" model continually adapts to the flowing plasma, applying the most resources to areas with lots of complex activity, while devoting less to areas that are simpler.

"Our model can calculate a solar activity-asteroid interaction in a few days," said Zimmerman. "It would probably take a few weeks – or a supercomputer – for a grid-type model to do the same at high resolution." Zimmerman is lead author of a paper on this research available online in the journal Icarus since April 4, 2014.

Zimmerman and his team plan to apply the model to see if the electrical activity around asteroids presents any potential hazards to human explorers.

"For example, understanding the electrical environment around an asteroid could help identify locations where astronauts can safely make first contact with the object," said co-author William Farrell of NASA's Goddard Space Flight Center in Greenbelt, Maryland. "If an astronaut is tethered to a spacecraft that is in sunlight and positively charged, and touches a negatively charged asteroid surface in shadow, there could be an unexpected current flow between the two systems upon contact. We simply can't speculate on the nature of that current without this model."

The model also can be used to predict interactions between an asteroid and the spacecraft itself. "One of the reasons we're visiting asteroids is because they are relatively pristine remnants from the formation of the solar system, so they give clues as to how the planets formed and life originated," says Farrell.

"However, spacecraft release gases (like water) that ionize, and these spacecraft-emitted ions likely will contaminate the surfaces of the asteroids we want to study. This new asteroid model will allow us to estimate the degree of ion collection and contamination over various regions." Farrell is the Principal Investigator of one of SSERVI's nine teams called the Dynamic Response of the Environment at Asteroids, the Moon, and moons of Mars (DREAM2), which provided a portion of the funding to develop the model.

The model shows that the solar wind flow at a small asteroid displays some phenomena that have been observed directly at the moon, giving confidence in its results. For example, a well-developed cloud of electrons ejected by sunlight forms on the asteroid's sunlit surface, while a low density supersonic wake streams behind the object in the solar wind flow. However, as with any computer model, these elements will have to be verified by actual measurements from future missions to asteroids.

"Eventually, we also plan to expand the capability of the model by making predictions and visualizations in three dimensions, as well as adding the capability to simulate electrically conductive exploration infrastructure as well as magnetic field effects," says Zimmerman.

This research was supported by an appointment to the NASA Postdoctoral Program at Goddard, administered by Oak Ridge Associated Universities through a contract with NASA. It also was supported by the NLSI and SSERVI, based and managed at NASA's Ames Research Center in Moffett Field, California.

SSERVI is a virtual institute that, together with international partnerships, brings science and exploration researchers together in a collaborative virtual setting. SSERVI is funded by the Science Mission Directorate and Human Exploration and Operations Mission Directorate at NASA Headquarters in Washington.

For more information about SSERVI and selected member teams, visit: http://sservi.nasa.gov 

Bill Steigerwald | Eurek Alert!

Further reports about: Asteroids Earth Electric Exploration Flight NASA Science Space activity electric charge solar wind surfaces

More articles from Physics and Astronomy:

nachricht NASA scientist suggests possible link between primordial black holes and dark matter
25.05.2016 | NASA/Goddard Space Flight Center

nachricht The dark side of the fluffiest galaxies
24.05.2016 | Instituto de Astrofísica de Canarias (IAC)

All articles from Physics and Astronomy >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Computational high-throughput screening finds hard magnets containing less rare earth elements

Permanent magnets are very important for technologies of the future like electromobility and renewable energy, and rare earth elements (REE) are necessary for their manufacture. The Fraunhofer Institute for Mechanics of Materials IWM in Freiburg, Germany, has now succeeded in identifying promising approaches and materials for new permanent magnets through use of an in-house simulation process based on high-throughput screening (HTS). The team was able to improve magnetic properties this way and at the same time replaced REE with elements that are less expensive and readily available. The results were published in the online technical journal “Scientific Reports”.

The starting point for IWM researchers Wolfgang Körner, Georg Krugel, and Christian Elsässer was a neodymium-iron-nitrogen compound based on a type of...

Im Focus: Atomic precision: technologies for the next-but-one generation of microchips

In the Beyond EUV project, the Fraunhofer Institutes for Laser Technology ILT in Aachen and for Applied Optics and Precision Engineering IOF in Jena are developing key technologies for the manufacture of a new generation of microchips using EUV radiation at a wavelength of 6.7 nm. The resulting structures are barely thicker than single atoms, and they make it possible to produce extremely integrated circuits for such items as wearables or mind-controlled prosthetic limbs.

In 1965 Gordon Moore formulated the law that came to be named after him, which states that the complexity of integrated circuits doubles every one to two...

Im Focus: Researchers demonstrate size quantization of Dirac fermions in graphene

Characterization of high-quality material reveals important details relevant to next generation nanoelectronic devices

Quantum mechanics is the field of physics governing the behavior of things on atomic scales, where things work very differently from our everyday world.

Im Focus: Graphene: A quantum of current

When current comes in discrete packages: Viennese scientists unravel the quantum properties of the carbon material graphene

In 2010 the Nobel Prize in physics was awarded for the discovery of the exceptional material graphene, which consists of a single layer of carbon atoms...

Im Focus: Transparent - Flexible - Printable: Key technologies for tomorrow’s displays

The trend-forward world of display technology relies on innovative materials and novel approaches to steadily advance the visual experience, for example through higher pixel densities, better contrast, larger formats or user-friendler design. Fraunhofer ISC’s newly developed materials for optics and electronics now broaden the application potential of next generation displays. Learn about lower cost-effective wet-chemical printing procedures and the new materials at the Fraunhofer ISC booth # 1021 in North Hall D during the SID International Symposium on Information Display held from 22 to 27 May 2016 at San Francisco’s Moscone Center.

Economical processing

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Networking 4.0: International Laser Technology Congress AKL’16 Shows New Ways of Cooperations

24.05.2016 | Event News

Challenges of rural labor markets

20.05.2016 | Event News

International expert meeting “Health Business Connect” in France

19.05.2016 | Event News

 
Latest News

LZH shows the potential of the laser for industrial manufacturing at the LASYS 2016

25.05.2016 | Trade Fair News

Great apes communicate cooperatively

25.05.2016 | Life Sciences

Thermo-Optical Measuring method (TOM) could save several million tons of CO2 in coal-fired plants

25.05.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>